Dental filling material

ABSTRACT

A dental filling material comprising a thermoplastic polymer. The thermoplastic polymer may be biodegradable. A bioactive substance may also be included in the filling material. The thermoplastic polymer acts as a matrix for the bioactive substance. The composition may include other polymeric resins, fillers, plasticizers and other additives typically used in dental materials. The filling material is used for the filing of root canals.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of application Ser. No.10/304,371, filed Nov. 26, 2002, which is a continuation-in-part ofapplication Ser. No. 10/279,609 filed Oct. 24, 2002, which claimspriority to provisional application Ser. No. 60/336,500 filed Oct. 24,2001.

FIELD OF THE INVENTION

This invention relates to filling materials for use in filling dentalcavities and for root canal treatments.

BACKGROUND OF THE INVENTION

Endodontics or root canal therapy is that branch of dentistry that dealswith the diseases of the dental pulp and associated tissues. One aspectof endodontics comprises the treatment of infected root canals, theremoval of diseased pulp tissues, followed by the biomechanicalmodification and the subsequent filling of the pulp cavity (root canal).Root canal therapy is generally indicated for teeth having soundexternal structures but having diseased, dead or dying pulp tissues.Such teeth may or may not generally possess intact enamel and dentin andare satisfactorily engaged with bony tissue. In such teeth, the pulptissue and excised portions of the root should be replaced by abiocompatible substitute. One technique for the preparation of a rootcanal involves creating a coronal access opening with a conventionaldental drill. A tool is used for gross removal of pulp material from theroot canal through the coronal access opening. The void formed isenlarged with reamers and/or files to result in a fully excavatedcavity. Debris is removed from this cavity by flushing and the cavity iscleansed to remove all diseased tissue. This process, while essential,results in a root canal that is weakened and susceptible to fracture.Following chemical antisepsis, the excavated canal is ready for filling.

A basic method involves inserting a filling cone into a root canal andcementing therein to obturate the canal. The common root canal fillingcone material is made from gutta-percha. Lateral condensation is amethod in which several filling cones, a primary cone and auxiliarycones, are inserted into a root canal. The primary cone is inserted andcemented to the seat of the root canal. Using a tapered spreader, theprimary cone is then squeezed against the side of the root canal and asecond cone is inserted and cemented into place. This process iscontinued until the root canal is completely obturated which can requireup to 10 to 15 filling cones. Vertical condensation of warm or hotgutta-percha is yet another method of sealing root canals. Aftercementing a primary cone short of the apex of the root canal, heatapplication is alternated with a series of smaller and smaller pluggersuntil the gutta-percha is moved to the apex. This is often possible whenthe smallest plugger approaches the apex of the tooth within 3 to 5millimeters. The space is then backfilled. Lateral canals are packed andsealed as a consequence of lateral expansion of a wave of heatedgutta-percha. Alternatively, small segments of gutta-percha can be usedin this method that are inserted into the root canal, heated in orderthat they can adhere to one another and each backfilled one at a timeuntil the root canal is filled. All three of these methods, the singlefilling cone, lateral condensation and vertical condensation apply rootcanal cement or sealer around the individual cones or in betweensegments as a binding agent.

Another method employs an injection gun that injects warm or hotgutta-percha filling material into a root canal. The injector initiallyplaces heated gutta-percha at the apical area of the root canal througha needle-like canula tip and fills the gutta-percha into any surroundingvoids/spaces under pressure or at the seat of the root canal which isthen condensed with a plugger into the root tip. The injector thenbackfills the root canal by injecting additional gutta-percha into theroot canal until it is obturated. A similar method involves heatinggutta-percha on a flexible metal or plastic carrier used to insert thegutta-percha into the root canal. The carrier may be a solid rod, or ahollow rod, situated in the center of a master cone. The rod isconnected to a handle which may be removed by slipping it out of thehollow rod, or cutting it off if it is a solid rod.

Most of the current methods employed in obturating a canal use agutta-percha material that is inert in nature and will not be absorbedor degraded by the living tissue if the root canal is overfilled andextends beyond the apex. It has been a challenge for dentists to controlthe exact amount of the material within the border of the root canal toavoid overfilling. The cold core of gutta-percha is not malleable sothat it cannot be molded to the canal walls, resulting in pooradherence. In addition, when heated gutta-percha cools to bodytemperature in the root, a uniform contraction takes place furtherreducing adherence to the walls of the canal. Moreover, gutta-perchamaterial is a polyisoprene rubber material in nature, which does nothave the capability to bond to most dental materials, especially whenthe root canal sealer is a polymer-based material. Due to poor adherenceand bonding, existing bacteria in the root canal can multiply or leakagemay result, causing bacteria to enter the canal from the mouth, whichcan lead to the persistence of an infection or other complications.Gutta-percha exhibits poor strength and brittleness. Dental gutta-perchapoints/cones tend to break in harsh conditions, e.g., sharply curvedroot canals, tight spaces during a root canal treatment, and the like.

It is desirable to provide a root canal filling material that bondseasily to sealants. It is preferable that the root canal fillingmaterial have proper strength and flexibility. It would be advantageousif the root canal filling material could be retrievable or dissolvable.It would be highly advantageous if the root canal filling material couldreduce or eliminate bacterial leakage. It would be beneficial if thecavity filling material and root canal filling material could bebioactive. It would be further advantageous if the root filling materialstrengthened the root.

SUMMARY OF THE INVENTION

These and other objects and advantages are accomplished by the fillingmaterial of the present invention comprising a thermoplastic polymer.The thermoplastic polymer is preferably a biodegradable polymer. Abioactive substance may be combined with the biodegradable thermoplasticpolymer. The thermoplastic polymer acts as a matrix for the bioactivesubstance. The composition may include other polymeric resins, fillers,plasticizers and other additives typically used in dental fillermaterials.

The filling material is used for the filling of dental cavities or rootcanals. The material may be placed in a root canal that has been openedto a predetermined dimension by use of endodontic files, to seal theapical end. If necessary, the filling material can be compacted towardthe apex, while it is still in the softened state, to ensure the apex isadequately sealed. If, by chance, the filling material is pushedslightly past the apex, or seeps through the apex, or comes in contactwith fluids in the mouth, the biodegradable material will disintegrateor break down and be absorbed or partially absorbed by the surroundingliving tissues. If a bioactive substance is present in the fillingmaterial, it will react with the tissue in the mouth, mending and/orgrowing tissue to fill in any gaps or openings.

BRIEF DESCRIPTION OF THE DRAWINGS

Features of the present invention are disclosed in the accompanyingdrawings, wherein similar reference characters denote similar elementsthroughout the several views, and wherein:

FIG. 1 is a graph showing bacterial leakage of test samples after 30days;

FIG. 2 is a graph showing bacterial leakage of test samples after 30days;

FIG. 3 is an elevational view of a sample placed in an Instron machinefor fracture testing;

FIG. 4 is an elevational view of the sample shown in FIG. 3;

FIG. 5 is an elevational view of an appliance having a filling materialthereon;

FIG. 6 is an elevational view of a post as an alternate carrier inaccordance with the invention;

FIG. 7 is an elevational view of an alternate embodiment of an alternatecarrier in accordance with the invention; and

FIG. 8 is an elevational view of yet another alternative embodiment ofthe invention.

DESCRIPTION OF THE INVENTION

As will be appreciated, the present invention provides a fillingmaterial for root canals and cavities comprising a thermoplasticpolymer. The thermoplastic polymer may be biodegradable. A bioactivesubstance may be combined with the biodegradable thermoplastic polymer.The thermoplastic polymer acts as a matrix for the bioactive substance.The composition may include other polymeric resins, fillers,plasticizers and other additives typically used in dental fillermaterials including, but not limited to, antibiotic, cariostatic,antibacterial, or other anti-inflammatory, biologically active,therapeutic materials, pigments and dyes. The composition may also beuseful for root canal sealants, implants and pulp capping materials.

It is important that the thermoplastic polymer bonds well to the rootcanal sealant that is applied to the root canal. The bond strength ofthe thermoplastic polymer to the root canal sealant is equal to orgreater than about 3 MPa, and preferably equal to or greater than about4 MPa and most preferably equal to or greater than about 5 MPa.

Suitable thermoplastic polymers for use as the matrix arepharmaceutically compatible. It is preferred that the polymers arebiodegradable by cellular action and/or by the action of body fluids.Examples of appropriate thermoplastic polymers include but are notlimited to polylactides, polyglycolides, polycaprolactones,polyanhydrides, polyamides, polyurethanes, polyesteramides,polyorthoesters, polydioxanones, polyacetals, polyketals,polycarbonates, polyorthocarbonates, polyphosphazenes,polyhydroxybutyrates, polyhydroxyvalerates, polyalkylene oxalates,polyalkylene succinates, polyethylene oxides,polyacrylates/methacrylates, poly(malic acid) polymers, polymaleicanhydrides, poly(methylvinyl) ethers, poly(amino acids), chitin,chitosan, and copolymers, terpolymers, or combinations or mixtures ofthe above materials.

Preferred materials are the polylactides, polyglycolides,polycaprolactones, and copolymers thereof. These polymers can be used toadvantage in the polymer system in part because they show excellentbiocompatibility. They produce little, if any, tissue irritation,inflammation, necrosis, or toxicity. In the presence of water, thesepolymers produce lactic, glycolic, and hydroxycaproic acid,respectively, which are readily metabolized by the body. Thepolylactides and polycaprolactones can also incorporate glycolidemonomer to enhance the resulting polymer's degradation. Thebiodegradable thermoplastic polymer may be present in an amount fromabout 10 to about 100 percent by weight.

The bioactive material may include any substance or metabolic precursorthereof, which is capable of promoting growth and survival of cells,tissues, and bone. Suitable bone growth promoting substances include butare not limited to bioglass, calcium phosphate, Portland cement,hydroxyapatite, tricalcium phosphate, a di- or polyphosphonic acid, ananti-estrogen, a sodium fluoride preparation, a substance having aphosphate to calcium ratio similar to natural bone, calcium hydroxide,other suitable calcium-containing compounds, and the like. A bone growthpromoting substance may be in the form of a particulate or fiber fillerin nano, micro or macro form, or mixtures thereof, bone chips, bonecrystals or mineral fractions of bone and/or teeth, a synthetichydroxyapatite, or other suitable form. The bioactive filler may bepresent in an amount of up to about 90 percent by weight.

The biodegradable thermoplastic polymers should have meltingtemperatures of about 50 to about 300° C., preferably about 60 to about250° C., and most preferably about 70 to about 200° C. The meltingtemperature of the polymers in these ranges facilitates the process ofcompounding the thermoplastic polymer with bioactive inorganicparticulates and other additives. Furthermore, the melting temperaturerange of the polymers also facilitates the application of the fillingmaterial made from the compounds into a root canal with conventionalaccessible heating methods.

Examples of additional polymeric resins useful in the fillingcomposition include, but are not limited to, polyamides, polyester,polyolefins, polyimides, polyarylates, polyurethanes, vinyl esters orepoxy-based materials, styrenes, styrene acrylonitriles, ABS polymers,polysulfones, polyacetals, polycarbonates, polyphenylene sulfides,polyarylsulfides, acrylonitrile-butadiene-styrene copolymers,polyurethane dimethacrylates (hereinafter abbreviated to “UDMA”,triethylene glycol dimethacrylate (hereinafter abbreviated “TEGDMA”),polyethylene glycol dimethacrylate (hereinafter abbreviated “PEGDMA”),urethane dimethacrylate (hereinafter abbreviated “UDMA”), hexane dioldimethacrylate (hereinafter abbreviated “1,6 HDDMA”) and polycarbonatedimethacrylate (hereinafter abbreviated “PCDMA”) and the like. Among theexamples given, the resins containing surface functional groups such asacrylate/methacrylate, epoxy, hydroxyl and others are preferred sincethey not only serve as plasticizers for the compositions but as adhesivecomponents as well for promoting the bonding between the compound and asealant. Preferred polymeric matrix materials include those based onacrylic and methacrylic monomers, for example those disclosed in U.S.Pat. Nos. 3,066,112, 3,179,623, and 3,194,784 to Bowen; U.S. Pat. Nos.3,751,399 and 3,926,906 to Lee et al., and commonly assigned U.S. Pat.No. 5,276,068 to Waknine (which are herein incorporated by reference).An especially preferred methacrylate monomer is the condensation productof bisphenol A and glycidyl methacrylate, 2,2′-bis[4-(3-methacryloxy-2-hydroxy propoxy)-phenyl]-propane (hereinafterabbreviated “BIS-GMA”).

Other fillers which may be used in addition to the bioactive materialinclude inorganic and organic particulates and fibrous fillers known inthe art including, but are not limited to, silica, silicate glass,quartz, zinc oxide, barium sulfate, barium silicate, strontium silicate,barium borosilicate, strontium borosilicate, borosilicate, lithiumsilicate, amorphous silica, bismuth compounds such as BiOCl, ammoniatedor deammoniated calcium phosphate and alumina, zirconia, tin oxide, andtitania, among other conventional fillers such as those disclosed incommonly assigned U.S. Pat. Nos. 4,544,359 and 4,547,531 to Waknine(which are incorporated herein by reference). Some of the fillers alsoact as radiopaque/high refractive index materials, such as apatites,silica glass fillers, calcium silicate based fillers, hydroxyapatites,barium sulfate, bismuth subcarbonate, ytterbium oxide, ytterbiumfluoride, ytterbium iodine, bismuth oxide, bismuth fluoride, bariumoxide, and tantalum oxide. Fibrous fillers also include, but are notlimited to, include glass, ceramic, metal, carbon, graphite, polymericsuch as cellulose, polyamide, aramid, polyester, polyaramid, acrylic,vinyl and modacrylic, polyolefin, polytetrafluorethylene, mixturesthereof, as well as other fibers known in the art. The fibers may be ofuniform or random length, unidirectional or multidirectional, orrandomly dispersed, and may be as short as about 3 to about 4millimeters (mm) or shorter. The fibers may also be in the form offabric as set forth in U.S. Patent No. 6,186,791, or as possiblereinforcing fibers, as used in U.S. Pat. Nos. 4,717,341 and 4,894,012 toGoldberg et al., all of which are hereby incorporated by reference.

Examples of plasticizers useful in the filling composition include, butare not limited to, polyol, polyolfin or a mixture thereof. Theplasticizer can be incorporated into the composition in the range of upto about 40 percent by weight, preferably up to about 30 percent byweight, and most preferably up to about 20 percent by weight.

In a method for restoring a root canal in accordance herein, the rootcanal is prepared by the dentist. This can involve inserting endodonticfiles or reamers into the canal to remove pulp, necrotic tissue, organicdebris, and other potential irritants. Thereafter, an etchant is appliedto the root canal wall. Examples of etchants include, but are notlimited to, organic acids or their derivatives such as an ethylenediamine tetra acetic acid (EDTA) solution, amino acid, acrylic acid,maleic acid, citric acid, tartaric acid, itaconic acid, 5-sulfosalicylicacid, propionic acid, lactic acid and the like; inorganic acids such asphosphoric acid, hydrochloric acid, sulfuric acid, nitric acid, and thelike. Useful etchants for the process herein disclosed are described incommonly assigned U.S. Pat. No. 6,537,563, which is hereby incorporatedby reference.

In general, the commercial dental etchants used for dentin surfaceconditioning/etching are all suitable for root canal etching purposes.Commercially available etching gels suitable for this purpose areavailable from Pentron Clinical Technologies, LLC as 10% phosphoric acidetching gel and 37% phosphoric acid etching gel. Preferably, the etchantis a self-etch bonding agent such as described in commonly owned,copending U.S. Application No. 20020019456, which is hereby incorporatedby reference. A commercially available self-etch primer useful herein isNanoBond™ self-etch primer from Pentron Clinical Technologies, LLC.Other examples of commercially available self-etch primer/adhesives areSE Bond™ available from Kuraray, Prompt L-Pop™ available from 3M/ESPEcompany, and iBond™ available from Kulzer.

Alternatively, if the etchant does not include an adhesive, a bondingagent may further be applied to the walls of the root canal. Examples ofbonding materials include, but are not limited to, dentalacrylate/methacrylate based resin adhesives. Commercially availablebonding agents include, but are not limited to, Bond-It® and Bond-1®bonding agents from Pentron Clinical Technologies, LLC, All Bond 2™ andOne Step™ from Bisco, Prime&Bond™ from Dentsply, ScotchBond™ from 3M,and PermaQuik™ from Ultradent. Thereafter, a sealant is applied into theroot canal. Examples of sealants include, but are not limited to,acrylate/methacrylate resin based root canal sealants, epoxy resin basedsealants, and the like and the sealants disclosed in commonly assignedU.S. Pat. No. 6,455,608, which is hereby incorporated by reference.Commercially available sealants include FiberFill™ root canal sealantfrom Pentron, AH-26™ from LD Caulk/Dentsply and EndoRez™ from Ultradent.After the sealant is applied, the filling material is inserted into thecanal. It may applied in a variety of ways including, but not limitedto, lateral condensation, vertical condensation of soft material, andsingle points of material either inserted individually or applied to acarrier and inserted into the canal via the carrier. The canal is thenfilled with a filling material that may or may not include a post toprovide added support for the remaining tooth structure. An artificialcrown, direct or indirect restoration, fixed-partial denture abutment,etc. can then be placed over the tooth to complete the toothrestoration.

The materials and process described herein provide superior sealing andfilling of the root canal. The materials used to seal and fill the rootcanal form a monoblock of material that is bonded to the wall of theroot canal to reduce or eliminate leakage of bacteria into the canal.Moreover, the filling materials described herein are easily removablefrom the root canal. One example of removing the filling material fromthe root is by dissolving the material in a dental solvent such aschloroform.

Leakage tests were performed over a thirty day period on samples ofteeth using various forms of filling materials. A split chambermicrobial leakage model was used wherein S. mutans or S. faecalis (seegroups below), which were placed in the upper chamber, could reach thelower chamber only through the obturated canal. A lower chamberconsisted of 15 ml of Basal Broth with Phenol Red indicator to which 1%sucrose was added. The specimens were checked every 24 hours over aperiod of 30 days for a change in the color of the broth or of the pHindicator from red to yellow (metabolism as acid production), whichindicated bacterial leakage. The average rate of leakage of bacteria wascompared between all groups over 30 days by usingCochran-Mantel-Haenszel row means score statistics. Leakage was assessedevery day for 30 days. The groups tested were as follows. Group 1consisted of ten teeth that were filled with gutta-percha, but withoutthe use of a sealer (Positive Control). Group 2 consisted of ten teethprepared as in Group 1, but the entire system was sealed to test itsability to stop bacteria from moving through it (Negative Control).Group 3 consisted of fifteen teeth having AH26 sealant applied and thenfilled laterally with gutta-percha and condensed (LT-AH26). Group 4consisted of fifteen teeth having AH26 sealant applied and then filledvertically with gutta-percha and condensed (VT-AH26). Group 5 consistedof fifteen teeth having AH26 sealant applied and then filled with Obturasoft gutta-percha (Obtura-AH26). Group 6 consisted of fifteen teethprepared and etched with a self etching primer, followed by applicationof a root canal sealant, followed by the lateral insertion of resinmaterial (resin percha) in accordance with the invention (LT ResinPercha). Group 7 consisted of fifteen teeth prepared and etched with aself etching primer, followed by application of a root canal sealant,followed by the vertical insertion of resin material (resin percha) inaccordance with the invention (VT Resin Percha). Groups 8 and 9 wereidentical to Groups 6 and 7, respectively, except that unlike Groups 1to 7 that used S. mutans bacteria, Groups 8 and 9 used S. faecalisbacteria. The results are shown in Table 1 below. TABLE 1 NUMBER OFLEAKAGE OF TEETH AFTER NUMBER OF DAYS GROUP TEETH 1 day 3 days 6 days 9days 12 days 15 days 18 days 21 days 24 days 27 days 30 days 1 10 10 1010 10 10 10 10 10 10 10 10 Positive Control 2 10 0 0 0 0 0 0 0 0 0 0 0Negative Control 3 15 0 0 6 10 12 13 13 13 13 13 13 LT-AH26 4 15 0 0 4 810 10 10 11 11 11 11 VT-AH26 5 15 0 0 8 10 14 14 14 14 14 14 14 ObturaAH26 6 15 0 0 0 0 1 1 1 1 2 2 2 LT Resin Percha 7 15 0 0 0 0 1 1 2 2 2 22 VT Resin Percha 8 15 0 1 1 1 1 1 2 2 2 2 2 LT Resin Percha 9 15 0 0 11 1 1 1 1 1 1 1 VT Resin Percha

As shown in Table 1, the materials of the invention used in Examples6-9, show leakage in only 1 or 2 of 15 teeth in a period of 30 dayscompared with conventional materials used in Examples 3 through 5, whichshowed leakage of most of the teeth over the same time period.

FIGS. 1 and 2 are graphs showing in-vitro leakage for Strep. mutans andEnterococcus faecalis, respectively, for test groups of 15 teeth usingthe test described above. In FIG. 1, PC, NC, L-GP, V-GP, L-RP and V-RPrefer to positive control, negative control, lateral-gutta-percha,vertical-gutta-percha, lateral-resin percha and vertical-resin percha,respectively. The resin percha used herein comprises Composition C asset forth in Table 3 below. Consistent with Table 1 above, the graph inFIG. 1 shows the positive control tooth having filling material withouta cement (PC) having leakage in all 15 teeth. The negative control,which is a normal tooth, showed no leakage after 30 days. Thegutta-percha inserted both laterally and vertically, show high leakagerates of 13 and 14 teeth, respectively, after 30 days. The resin perchaof the invention showed very low leakage of only 2 teeth after 30 days.

The graph in FIG. 2 representing leakage of Enterococcus faecalis intest groups of 15 teeth is also consistent with Table 1 and FIG. 1. Asexpected, the positive control shows leakage of all 15 teeth and thenegative control shows no leakage. The laterally placed and verticallyplaced resin percha show low leakage of only 2 teeth and 1 tooth,respectively.

The following examples illustrate the invention.

EXAMPLE 1

Extracted central incisor teeth were prepared with root canal files tostandard sizes so that the remaining walls of the teeth were of asimilar size. The roots were restored as follows Group 1 (15teeth)—positive control—no root canal filling placed. Group 2 (15teeth)—root canals filled with lateral condensation gutta-percha andAH26 sealer. Group 3 (15 teeth)—root canals filled with verticalcondensation gutta-percha and AH26 root canal sealer. Group 4 (15teeth)—root canals walls were prepared with the self etch primer, filledwith root canal sealant sealer and then filled vertically with resinpercha in accordance with the invention. All roots were placed in acontainer with 100% humidity for 2 weeks until the strength tests wereperformed. After two weeks the teeth were mounted into a plastic ringwith commercial resin to a level that left 8 mm of root above the resin.The rings were mounted into an Instron machine in which a ballattachment was-placed so as to create a wedge-like force along the longaxis of the tooth when activated. Reference is hereby made to FIGS. 3and 4, which show the placement of the samples in the Instron machine.When the correct position of the ball on the tooth was confirmed, theInstron machine was activated so that a slowly increasing force wasapplied to the root until fracture occurred. The resistance to fracture(fracture force) for each tooth in each group was recorded and the meanfracture values for the groups are compared in Table 2 below. TABLE 2Group 1 - Control 360 lbs Group 2 - 331 lbs GP Lateral Group 3 - 380 lbsGP Vertical Group 4 - 460 lbs RP vertical

As can be seen from the results in Table 2, the groups in whichgutta-percha was used (Groups 2 and 3) were no different from thecontrol group (Group 1) having no root canal filling. The resin perchagroup (Group 4) showed a 22% increase in strength over the control(Group 1).

EXAMPLE 2

A composition comprising polycaprolactone available from Union Carbidein an amount of about 40%, a bioactive glass having a compositionsimilar to Bioglass™ (available from by U.S. Biomaterials) in an amountof about 30%, USP grade zinc oxide in an amount of about 20% and bariumsulfate as a radio-opacifying agent in an amount of about 10% wasmanufactured. The method of forming the composition involved heating thepolycaprolactone at about 70° C. to a softened state. The remainingingredients were then added and mixed under the action of kneading,pressing, or mixing to blend into the polycaprolactone completely toform a homogenous dough. The formed compound was then ready forapplication to the carrier device.

EXAMPLE 3

A composition comprising polycaprolactone in an amount of about 30%,caprolactone (methacryloxy)ethyl ester (CMEE) in an amount of about 10%,tricalcium phosphate in an amount of about 30%, and zirconium oxide inan amount of about 10% was manufactured. The method of forming thecomposition involved heating the polycaprolactone (available from UnionCarbide) at about 70° C. to a softened state. The remaining ingredientswere then added and mixed under the action of kneading, pressing, ormixing to blend into the polycaprolactone completely to form ahomogenous dough. The formed compound was then ready for application tothe carrier device.

The following Table 3 sets forth examples of the filling materialcompositions made similar to the methods described in Examples 2 and 3above. TABLE 3 Composition WEIGHT (%) A B C D E P767* 40 30 21 25 P787*9 27 PEGDMA(400) 5 8 UDMA 10 CMEE** 10 Bioactive glass 30 10 21.5 30 ZnO20 10 21.5 25 25 BaSO₄ 20 22 20 BiOCl 10 Ca(OH)₂ 20 Ca₃(PO₄)₂ 20 ZrO₂ 10*P767 and P787 are polycaprolactone resins sold under the trade name ofTONE ™ POLYMER by Dow Chemical Co.**CMEE is caprolactone (methacryloxy) ethyl esterThe compositions were then prepared for bonding strength tests asfollows:

Sample Preparation for Bonding Tests

The compositions from Table 3 above were softened at about 80° C. in aconvection oven. While the materials were at a workable consistency,they were placed in 15 mm diameter and 1.2 mm thickness steel moldsbetween two glass slides and were cooled down to bench temperature.Sample disks were formed and the glass slides and molds were removed.Some trimming was necessary to remove the flashes from the edge. Fivediscs were prepared for each test material.

The sample disks were then mounted into a cold-cured acrylic mountingmaterial in a splitable cylindrical TEFLON™ mold of a 20 mm diameter andabout a 30 mm height, leaving one side of the disk exposed. Atwo-component self curable A2 shaded Cement-It™ C&B Universal Cement(Pentron Corp., Wallingford, Conn.), which is a methacrylate resincement, was used to make a composite button and was bonded directly tothe exposed sample surfaces. Number five (#5) Gelatin capsules (TorpacInc. NJ) were used to load the cement and were placed directly onto thesurfaces under a load of 500 grams on a Bencor testing device (DenvilleEngineering, CA) until the cement hardened. The cement has a settingtime of approximately 4 minutes after the two components are mixed.After one hour of bench setting, the bonded samples were debonded with apush shear mold in a Bencor test device under a crosshead speed of 0.02in/minute. The maximum load at which the cement cylinders broke from thesample surfaces was recorded. Bonding strengths were calculated usingthe load divided by the contact surface area of the cement cylinder.

The following Table 4 sets forth bonding strengths of the fillingcompositions in Table 3 along with a gutta-percha composition forcomparison. TABLE 4 Compositions Bond Strength, MPa (S.D.) A 3.2 (1.1) B5.5 (2.3) C 6.5 (1.9) D 6.8 (0.7) E 6.8 (1.2) Gutta-percha Control*   0(Samples all failed before testing)*The control is a dental gutta-percha material available from Endodent,Inc. Duart, CA

Transverse Deflection Tests

To test the flexibility of the compositions herein, a testing apparatusfor the transverse deflection test as described in ADA specificationNumber 12 for Denture Base Polymers was adopted for the test. The testsamples were made into bars of 50×3×3 mm in a TEFLON splitable moldwhile the materials were at a soft stage. A 500 gram weight was appliedonto the center of the test sample through the loading nose. The spanbetween the two supports was 30 mm. The still load was removed after oneminute (if the sample had not broken during the standing period) and themaximum deflection distance was measured and recorded. Three testsamples were run for each test material. The test results are shown inTable 5. TABLE 5 Maximum Deflection Time of Test Samples CompositionsDistance (mm) withstanding the load) A 6-8 Full minute without break C7-9 Full minute without break Gutta-percha 1-3 1-2 seconds (Broke almostControl instantly after applied the load)

The results of the inventive materials are shown to have superiorresults over the gutta-percha material.

The bioactive material can be miscible in the polymer to provide ahomogeneous mixture with the polymer, or insoluble in the polymer toform a suspension or dispersion with the polymer. The filling materialmay be in the form of a cone to be inserted into a canal. The cone maybe inserted into the canal using a file or similar instrument, or it maybe attached to a file, shaft or similar carrier which instrument is theninserted into the canal with the cone thereon. After insertion, thecarrier is removed or the excess of the cone is cut off as in aconventional gutta-percha cone application from the root canal.

Alternatively, the material may be softened and compacted toward theapex, while it is still in the softened state, to ensure the apex isadequately sealed. This may be done by a backfilling technique whereby,for example, the material is heated and injected into the canal using adevice having a needle, such as the Obtura II device available fromObtura/Spartan, Fenton, Mo.

If, by chance, the filling material is pushed slightly past the apex, orseeps through the apex, or comes in contact with fluids in the mouth,the biodegradable material will disintegrate or break down and beabsorbed or partially absorbed by the surrounding living tissues and thebioactive substance present in the filling material will react withtissue in the mouth, mending and/or growing tissue to fill any gaps oropenings.

Commonly assigned U.S. Pat. No. 6,455,608 is directed to dentalcompositions comprising degradable polymers for use as root canalsealants, implants and pulp capping materials and is hereby incorporatedby reference. The compositions use polymerizable and degradablemacromonomers to provide precursors for forming biodegradable andbiocompatible polymers upon a chemical reaction, which advantageouslyallow for tissue regrowth.

As yet another alternative, the filling material may be integrallyformed on a post whereby a single post unit comprises a combinedendodontic post and tip of filling material. To use the post unit, thetip of the device is softened by placing in an oven or heater to heatand soften the filling material or chemically treating to soften thematerial. The device will then be placed in a root canal that has beenopened to a predetermined dimension by use of endodontic files, to sealthe apical end. If necessary, the filling material can be compactedtoward the apex, while it is still in the softened state, to ensure theapex is adequately sealed. The post may then be cemented into place bylining the canal walls with a bonding agent and filling the interfacebetween the post and the walls of the canal with a resin cement such asa dual cure cement, a light cure cement or a self cure cement such asFiberFill™ RCS root canal sealant or Cement-It® Universal cement, bothavailable from Pentron Clinical Technologies, LLC in Wallingford, Conn.This will result in a coronal seal of the canal via a resin restorativematerial and an apical seal of the canal by means of a filling materialand sealant. The remaining portion of the post, extendingsupra-gingivally, will be used to build a core around it. Any excesswill be cut off. One length of the device will be longer to accommodatethe longer roots in anterior teeth. Another length will be shorter toaccommodate smaller roots in the molar region. Various diameters mayalso be provided to accommodate the different sizes of root canals. Thebonded flexible post may strengthen the tooth to prevent subsequent rootfractures.

Reference is made to FIGS. 3 through 6 which show carriers having thefilling material applied to the tip of the carrier. FIG. 3 shows anappliance 10 having a handle 12 and an elongated shaft 14. Shaft 14 hasa proximal end 14 p and a distal end 14 d that fits in a root canal. Asliding support 16 is positioned between shaft 14 and handle 12 to serveas an indicator of the depth of the canal and to help maintain thecarrier in place. After the appliance is inserted in the canal, slidingsupport 16 is moved to the point at the top of the canal. Fillingmaterial 18, containing a biodegradable thermoplastic polymer and abioactive filler, is positioned on the shaft, starting at the proximalend and continuing down, over the distal end. Reference is hereby madeto commonly assigned U.S. Pat. Nos. 6,447,297 and 6,428,319, andcommonly assigned U.S. patent application Ser. No. 10/164,512 filed Jun.6, 2002, each directed to posts or obturators having filling materialsintegrally formed thereon, and all of which are hereby incorporated byreference.

Turning to FIG. 4, a post unit 20 is shown comprising a post section 21and a cone or tip section 24. Tip section 24 comprises a flexible rod orcone comprising a biodegradable thermoplastic polymer in combinationwith a bioactive substance for filling the apex of the canal. Thefilling material may include additives typical in the dental field suchas plasticizing, antibiotic, cariostatic, antibacterial, or otheranti-inflammatory, biologically active or therapeutic materials.

Post section 21 comprises a main body or endodontic portion 22 and acarrier or apical portion 23, which is located at the apical end of postunit 20. Main body 22 may be a solid rod of circular or other suitablecross-section comprising a substantially smooth surface or may comprisea plurality of frustoconical sections arranged coaxially along thelongitudinal axis of main body 22. Preferably, main body 22 hasconsistent width along the longitudinal axis thereof whereasfrustoconical sections each have the same tapered width and same length.It is possible to vary the width and/or length of main body 22 and/orvary the tapered width and/or length of frustoconical sections along thelongitudinal axis of main body 22.

Carrier 23 is preferably an extension of main body 22 of post section 21and is of very fine diameter to accommodate tip section 24 ofthermoplastic material of post unit 20. In one method of manufacturewhich will be discussed hereinafter, post section 21 is manufacturedfrom a rod of material that is cut or machined at the apical end toresult in carrier 23 having a very small width or diameter in comparisonto main body 22. Carrier 23 is of small diameter to allow enough area toform tip section 24 thereon, and also of enough strength and integrityto accommodate the filling material as discussed above. As stated above,carrier 23 is preferably an extension of main body 22 and is shownhaving constant diameter along the length thereof, but may be of anyshape or size sufficient to hold tip section 24 thereon. Post section 21may be fabricated of any material to provide a flexible apical portionand a more rigid endodontic and/or coronal or supracoronal portion, suchas metal, plastic, ceramic, polymeric, composite, or other materialsuitable for placement in the mouth. Composite materials include but arenot limited to filler reinforced composite materials and fiberreinforced composite materials comprising the reinforcing component in apolymeric matrix material such as those composite materials listed inU.S. Pat. Nos. 4,717,341 and 4,894,012 to Goldberg et al., U.S. Pat. No.6,039,569 to Prasad et al., U.S. Pat. No. 6,030,220 to Karmaker et al,U.S. Pat. No. 5,564,929 to Alpert, and U.S. Pat. No. 5,919,044 toSicurelli, Jr. et al., all of which are hereby incorporated byreference. The fiber reinforced composite material may comprise fibersin the form of long, unidirectional, continuous filaments which arepreferably at least partially aligned and oriented along thelongitudinal dimension of the component with alignment normal orperpendicular to that dimension also possible. The fibers may be ofuniform or random length, unidirectional or multidirectional, orrandomly dispersed, and may be as short as about 3 to about 4millimeters (mm) or shorter. The fibers may also be in the form offabric as set forth in copending Ser. No. 09/280,760 filed Mar. 29,1999, now U.S. Pat. No. 6,186,791, and may include any of the attributesof the post described therein, the contents all of which are herebyincorporated by reference. Due to the improved structural integrity, theamount of fibers in the structural component preferably equals at leastabout 20% by weight (wt %) and preferably about 20 wt % to about 70 wt%. Possible reinforcing fibers, which are preferably used in accordancewith U.S. Pat. Nos. 4,717,341 and 4,894,012 to Goldberg et al. (whichare herein incorporated by reference), include glass, ceramic, metal,carbon, graphite, polymeric such as cellulose, polyamide, aramid,polyester, polyaramid, acrylic, vinyl and modacrylic, polyolefin,polytetrafluorethylene, mixtures thereof, as well as other fibers knownin the art. One preferred version of the device is comprised ofunidirectional microfilamentous glass fibers bundled in a resin matrix.

In order to enhance the bond between the fibers and polymeric matrix,thereby enhancing the reinforcing effect, the fibers may be silanized orotherwise treated such as by grafting functional monomers to obtainproper coupling between the fibers and the resin matrix. Silanizationrenders the fibers hydrophobic, reducing the water sorption andimproving the hydrolytic stability of the composite material, rendersthe fibers organophilic, improving wetting and mixing, and bonds thefibers to the polymeric matrix. Typical silane is A-174 (p-methacrylatepropyl tri-methoxy silane), produced by OSI Specialties, New York.

The polymeric matrix is selected from those known in the art of dentalmaterials, including, but not limited to, polyamides, polyester,polyolefins, polyimides, polyarylates, polyurethanes, vinyl esters orepoxy-based materials, styrenes, styrene acrylonitriles, ABS polymers,polysulfones, polyacetals, polycarbonates, polyphenylene sulfides,polyarylsulfides, acrylonitrile-butadiene-styrene copolymers,polyurethane dimethacrylates (hereinafter abbreviated to PUDMA), and thelike. Preferred polymeric matrix materials include those based onacrylic and methacrylic monomers, for example those disclosed in U.S.Pat. Nos. 3,066,112, 3,179,623, and 3,194,784 to Bowen; U.S. Pat. Nos.3,751,399 and 3,926,906 to Lee et al.; and commonly assigned U.S. Pat.Nos. 5,276,068 to Waknine (which are herein incorporated by reference).An especially preferred methacrylate monomer is the condensation productof bisphenol A and glycidyl methacrylate, 2,2′-bis[4-(3-methacryloxy-2-hydroxy propoxy)-phenyl]-propane (hereinafterabbreviated “BIS-GMA”).

The polymer matrix, which typically includes polymerization initiators,polymerization accelerators, ultra-violet light absorbers,anti-oxidants, fluorescent whitening agents, free radical initiators,and/or other additives well known in the art, may be visible lightcurable, self-curing, dual curing, or vacuum, heat, or pressure curablecompositions, as well as any combination thereof. Heat and pressure orvacuum curable compositions include a heat cure initiator such asbenzoyl peroxide, 1,1′-azobis(cyclohexanecarbo-nitrile) or other freeradical initiators. The preferred polymeric matrix is a light and heatcurable matrix, wherein light effects partial cure of the polymermatrix, while final curing is by heat under controlled atmosphere.

Fillers may be present in addition to or instead of fibers in an amountup to about 80 wt %, and preferably about 70 wt %. If fibers arepresent, the amount of filler is present in an amount of up to about 30wt % of one or more fillers known in the art and used in dentalrestorative materials. Suitable fillers include those capable of beingcovalently bonded to the polymeric matrix itself or to a coupling agentthat is covalently bonded to both. Fillers include silica, silicateglass, quartz, barium silicate, strontium silicate, barium borosilicate,strontium borosilicate, borosilicate, lithium silicate, amorphoussilica, ammoniated or deammoniated calcium phosphate and alumina,zirconia, tin oxide, and titania, among other conventional fillers suchas those disclosed in commonly assigned U.S. Pat. Nos. 4,544,359 and4,547,531 to Waknine (which are incorporated herein by reference), whilepossible coupling agents include silanes, zirconates, and titanates. Ifthe post is manufactured from a composite material, it is preferably incompletely cured or hardened state.

Examples of metals useful as post section 21 include but are not limitedto metals or alloys of Pd, Pt, Rh, Ir, Au, Ag, Ti, Co, Mo and mixturesthereof such as AgPd, AuPtPd, TiAlFe, TiAIV, CoCrMo, stainless steel andbrass. Ceramic materials useful in the fabrication of post section 21include but are not limited to alumina, zirconia, mullite, spinel,porcelain, titania, lithium disilicate, leucite, amorphous glass,lithium phosphate, and combinations thereof, or any high strengthceramic material which can withstand the stresses created in the mouth.

Carrier 23 preferably comprises a smooth surface, although it is in noway limited to such and may be of any surface suitable for applicationof filling material thereon. The post may be provided in an opaque toothcolor or it may be colored similar to a tooth's pulp for enhancedesthetics. The post may include an appropriate amount of radiopaquematerial such as titanium oxide, barium sulfate, and similar materialsknown in the dental industry to insure x-ray documentation which may beadded to the post material during manufacture thereof. After postsection 21 has been manufactured, carrier 23 of post section 21 is thencoated with a filling material such as set forth above to obtain conesection 24 thereon. The filling material may be applied by any knownmeans such as dipping, injection molding, hand rolling, and the like.

To use the post unit, the device may be used as is, or may be heated byplacing in or near an oven or heater to heat and soften the fillingmaterial or dipped in a chemical solution such as chloroform to softenthe filling material. The device will then be placed in a root canalthat has been opened to a predetermined dimension by use of endodonticfiles, to seal the apical end. If necessary, the filling material can becompacted toward the apex, while it is still in the softened state, toensure the apex is adequately sealed. The post is then cemented intoplace by lining the canal walls with a bonding agent and filling theinterface between the post and the walls of the canal with a resincement, such as a dual cure cement. This will result in a coronal sealof the canal via resin restorative material and an apical seal of thecanal by means of filling material and sealant. The remaining portion ofthe post, extending supra-gingivally, will be used to build a corearound it, and if necessary, for placement of a crown thereon. Anyexcess of the post will be cut off. One length of the device will belonger to accommodate the longer roots in anterior teeth. Another lengthwill be shorter to accommodate smaller roots in the molar region.

FIG. 5 shows a post unit 30 comprises a post section 32 fabricated offiber reinforced composite material. Post section 32 includes main body34 and carrier 36. Carrier 36 is coated with a filling material toobtain cone section 38 thereon. As shown in the drawing, main body 34 istapered to provide ease of placement into the canal. The cross-sectionof post unit 30 may be smaller than the cross-section of a standard postto fit in thinner or smaller auxiliary canals which are normally filledwith a thermoplastic material. Accordingly, post unit 30 can act as anobturator. As an obturator, better support is provided due to thefiber-reinforced composite structural component 34 upon which conesection 38 is applied in comparison to using only a thermoplasticmaterial as an obturator. Moreover, the obturator may be easily cementedin place in the canal. Post unit 30 may also include a handle 40 whichis beneficial when the post unit is used as an obturator. Handle 40 maybe any filled or unfilled polymeric material, such as those mentionedabove and used in the fabrication of the post.

FIG. 6 is directed to an obturator 40 having filling core or point 42and a handle 44. Filling core 42 is a shaft 46 having a proximal end 46p and a distal end 46 d that fits in a root canal. A sliding support 48is positioned between shaft 46 and handle 44 to serve as an indicator ofthe depth of the canal and to help maintain the obturator in place.After the appliance is inserted in the canal, sliding support 48 ismoved to the point at the top of the canal. Obturator 40 is cut off atthe point desired to fit the canal. Filling core 42 containing abiodegradable thermoplastic polymer and optionally, a bioactive filler,in the form of shaft 46, fills the canal. The filling core 42 and handle44 are a single unit fabricated of a biodegradable thermoplastic polymerand optionally, a bioactive filler. Alternatively, the filling core ismade of a biodegradable thermoplastic polymer and optionally, abioactive filler and the handle may be fabricated of any know materialincluding but not limited to metal, plastic, composite, ceramic, glassor polymeric material.

The compositions of the inventive materials have a radiopacity similarto gutta-percha materials.

While various descriptions of the present invention are described above,it should be understood that the various features can be used singly orin any combination thereof. Therefore, this invention is not to belimited to only the specifically preferred embodiments depicted herein.Further, it should be understood that variations and modificationswithin the spirit and scope of the invention may occur to those skilledin the art to which the invention pertains. Accordingly, all expedientmodifications readily attainable by one versed in the art from thedisclosure set forth herein that are within the scope and spirit of thepresent invention are to be included as further embodiments of thepresent invention. The scope of the present invention is accordinglydefined as set forth in the appended claims.

1. A filling material for cavities and root canals comprising: athermoplastic polymer having a bond strength when bonded to a root canalsealant equal to or greater than about 3 MPa; and optionally, abioactive filler.
 2. The filling material of claim 1 wherein thethermoplastic polymer comprises a biodegradable polymer.
 3. The fillingmaterial of claim 1 wherein the thermoplastic polymer is present in anamount from about 10 percent to about 100 percent by weight.
 4. Thefilling material of claim 1 wherein the bioactive filler is present inan amount of up to about 90 percent by weight.
 5. The filling materialof claim 1 wherein the biodegradable polymer comprises polylactides,polyglycolides, polycaprolactones, polyanhydrides, polyamides,polyurethanes, polyesteramides, polyorthoesters, polydioxanones,polyacetals, polyketals, polycarbonates, polyorthocarbonates,polyphosphazenes, polyhydroxybutyrates, polyhydroxyvalerates,polyalkylene oxalates, polyethylene oxides, polyacrylates/methacrylates,polyalkylene succinates, poly(malic acid) polymers, polymaleicanhydrides, poly(methylvinyl) ethers, poly(amino acids), chitin,chitosan, and copolymers, terpolymers, or combinations or mixturesthereof.
 6. The filling material of claim 1 wherein the bioactive fillercomprises bioglass, calcium phosphate, Portland cement, hydroxyapatite,tricalcium phosphate, a di- or polyphosphonic acid, an anti-estrogen, asodium fluoride preparation, a substance having a phosphate to calciumratio similar to natural bone, or mixtures thereof.
 7. The fillingmaterial of claim 1 wherein the bioactive filler comprises bone chips,bone crystals, mineral fractions of bone or teeth, or mixtures thereof.8. The filling material of claim 1 wherein the bioactive fillercomprises particulate or fibrous filler in nanosize, microsize,macrosize form, or mixtures thereof.
 9. The filling material of claim 1further comprising a plasticizer.
 10. The filling material of claim 9wherein the plasticizer is present in an amount of up to about 90percent by weight.
 11. The filling material of claim 9 wherein theplasticizer comprises polyol, polyolfin or a mixture thereof.
 12. Thefilling material of claim 1 further comprising an adhesive.
 13. Thefilling material of claim 12 wherein the adhesive comprises acrylate,methacrylate, or a mixture thereof.
 14. The filling material of claim 1further comprising a polymeric resin, additional filler, pigment, dye,antibiotic, cariostatic, antibacterial, anti-inflammatory, biologicallyactive or therapeutic material.
 15. The filling material of claim 14wherein the polymeric resin comprises polyamides, polyesters,polyolefins, polyimides, polyarylates, polyurethanes, vinyl estersepoxy-based materials, styrenes, styrene acrylonitriles, ABS polymers,polysulfones, polyacetals, polycarbonates, polyphenylene sulfides,polyarylsulfides, acrylonitrile-butadiene-styrene copolymers,polyurethane dimethacrylates, triethylene glycol dimethacrylate,polyethylene glycol dimethacrylate, urethane dimethacrylate, hexane dioldimethacrylate, polycarbonate dimethacrylate, the condensation productof bisphenol A and glycidyl methacrylate, 2,2′-bis[4-(3-methacryloxy-2-hydroxy propoxy)-phenyl]-propane and mixturesthereof.
 16. The filling material of claim 14 wherein the additionalfiller comprises a radiopacifying filler.
 17. The filing material ofclaim 14 wherein the additional filler comprises silica, silicate glass,quartz, zinc oxide, barium sulfate, barium silicate, strontium silicate,barium borosilicate, strontium borosilicate, borosilicate, lithiumsilicate, amorphous silica, bismuth compounds such as BiOCl, ammoniatedor deammoniated calcium phosphate and alumina, zirconia, tin oxide, andtitania, apatites, silica glass fillers, calcium silicate based fillers,hydroxyapatites, barium sulfate, bismuth subcarbonate or mixturesthereof.
 18. The filling material of claim 14 wherein the additionalfiller comprises a fibrous filler.
 19. The filling material of claim 18wherein the fibrous filler comprises glass, ceramic, metal, carbon,graphite, or polymeric fibers.
 20. The filling material of claim 19wherein the polymeric fibers comprise cellulose, polyamide, aramid,polyester, polyaramid, acrylic, vinyl, modacrylic, polyolefin,polytetrafluorethylene, or mixtures thereof.
 21. An appliance forapplying a filling material to a root canal of a tooth comprising: ahandle; a shaft; and filling material disposed on the shaft, wherein thefilling material comprises a thermoplastic polymer having a bondstrength when bonded to a root canal sealant equal to or greater thanabout 3 MPa; and optionally, a bioactive filler.
 22. The appliance ofclaim 21 wherein the biodegradable thermoplastic polymer comprisespolylactides, polyglycolides, polycaprolactones, polyanhydrides,polyamides, polyurethanes, polyesteramides, polyorthoesters,polydioxanones, polyacetals, polyketals, polycarbonates,polyorthocarbonates, polyphosphazenes, polyhydroxybutyrates,polyhydroxyvalerates, polyalkylene oxalates, polyethylene oxides,polyacrylates/methacrylates, polyalkylene succinates, poly(malic acid)polymers, polymaleic anhydrides, poly(methylvinyl) ethers, poly(aminoacids), chitin, chitosan, and copolymers, terpolymers, or combinationsor mixtures thereof.
 23. The appliance of claim 21 wherein the bioactivefiller comprises bioglass, calcium phosphate, Portland cement,hydroxyapatite, tricalcium phosphate, a di- or polyphosphonic acid, ananti-estrogen, a sodium fluoride preparation, a substance having aphosphate to calcium ratio similar to natural bone, or mixtures thereof.24. An endodontic post comprising: a post section; and a tip section,wherein the tip section comprises a filling material, wherein thefilling material comprises a thermoplastic polymer having a bondstrength when bonded to a root canal sealant equal to or greater thanabout 3 MPa; and optionally, a bioactive filler.
 25. The endodontic postof claim 24 wherein the tip section is integral to the post section. 26.The endodontic post of claim 24 wherein the post section is fabricatedof metal, plastic, composite, ceramic, glass or polymeric material. 27.The endodontic post of claim 24 wherein the thermoplastic polymercomprises polylactides, polyglycolides, polycaprolactones,polyanhydrides, polyamides, polyurethanes, polyesteramides,polyorthoesters, polydioxanones, polyacetals, polyketals,polycarbonates, polyorthocarbonates, polyphosphazenes,polyhydroxybutyrates, polyhydroxyvalerates, polyalkylene oxalates,polyethylene oxides, polyacrylates/methacrylates, polyalkylenesuccinates, poly(malic acid) polymers, polymaleic anhydrides,poly(methylvinyl) ethers, poly(amino acids), chitin, chitosan, andcopolymers, terpolymers, or combinations or mixtures thereof.
 28. Theendodontic post of claim 24 wherein the bioactive filler comprisesbioglass, calcium phosphate, Portland cement, hydroxyapatite, tricalciumphosphate, a di- or polyphosphonic acid, an anti-estrogen, a sodiumfluoride preparation, a substance having a phosphate to calcium ratiosimilar to natural bone, or mixtures thereof.
 29. A method for restoringthe root canal of a tooth comprising: preparing the root canal; applyinga sealant into the root canal; inserting a filling material into thecanal, wherein the filling material comprises a thermoplastic polymerand optionally, a bioactive filler, wherein the thermoplastic polymerbonds to the sealant at a bond strength equal to or greater than about 3MPa.
 30. The method of claim 29 wherein the step of preparing the rootcanal comprises applying an etchant to the walls of the root canal. 31.The method of claim 30 wherein the etchant is a self etchant.
 32. Themethod of claim 30 wherein the self etchant comprises an adhesivematerial.
 33. The method of claim 29 further comprising applying abonding agent to the walls of the root canal after the root canal hasbeen prepared.
 34. The method of claim 33 wherein the bonding agent,sealant and filling material from a monoblock.
 35. The method of claim31 wherein the self-etchant, sealant and filling material form amonoblock.
 36. The method of claim 29 wherein the filling material issoftened prior to insertion into the canal.
 37. The method of claim 29wherein the filling material is removable.
 38. The method of claim 29wherein the filling material is dissolvable.
 39. The method of claim 38wherein the filling material is dissolvable in a dental solvent.
 40. Themethod of claim 39 wherein the dental solvent comprises chloroform. 41.The method of claim 29 wherein the filing material comprises a singlepiece of material.
 42. The method of claim 41 wherein the single pieceof material is shaped and sized to fit snugly into the root canal. 43.The method of claim 29 wherein the filing material is shaped in the formof a cone.
 44. The method of claim 29 further comprising, afterinserting the filling material into the canal, heating and condensingthe filling material to create more space, and inserting additionalpieces of filling material into the space.
 45. The method of claim 29wherein the filling material is inserted into the root canal laterallyand condensed and this step is repeated until the root canal issufficiently filled.
 46. The method of claim 29 wherein the fillingmaterial is inserted into the root canal vertically and condensed andthis step is repeated until the root canal is sufficiently filled. 47.The method of claim 29 wherein the filling material comprises a singlepoint of material that is inserted into the root canal to sufficientlyfill the canal.
 48. The method of claim 47 wherein the single point ofmaterial is disposed on a carrier and inserted into the canal via thecarrier.
 49. The method of claim 29 wherein the thermoplastic polymercomprises polylactides, polyglycolides, polycaprolactones,polyanhydrides, polyamides, polyurethanes, polyesteramides,polyorthoesters, polydioxanones, polyacetals, polyketals,polycarbonates, polyorthocarbonates, polyphosphazenes,polyhydroxybutyrates, polyhydroxyvalerates, polyalkylene oxalates,polyethylene oxides, polyacrylates/methacrylates, polyalkylenesuccinates, poly(malic acid) polymers, polymaleic anhydrides,poly(methylvinyl) ethers, poly(amino acids), chitin, chitosan, andcopolymers, terpolymers, or combinations or mixtures thereof.
 50. Themethod of claim 29 wherein the bioactive filler comprises bioglass,calcium phosphate, Portland cement, hydroxyapatite, tricalciumphosphate, a di- or polyphosphonic acid, an anti-estrogen, a sodiumfluoride preparation, a substance having a phosphate to calcium ratiosimilar to natural bone, or mixtures thereof.
 51. The method of claim 29wherein the bioactive filler comprises bone chips, bone crystals,mineral fractions of bone or teeth, or mixtures thereof.
 52. The methodof claim 29 wherein the bioactive filler comprises particulate orfibrous filler in nanosize, microsize, macrosize form, or mixturesthereof.
 53. The method of claim 29 wherein the filling material furthercomprises a plasticizer.
 54. The method of claim 53 wherein root canalwherein the plasticizer comprises polyol, polyolefin or a mixturethereof.
 55. The method of claim 29 wherein filling material furthercomprises an adhesive.
 56. The method of claim 55 wherein the adhesivecomprises acrylate, methacrylate, or a mixture thereof.
 57. The methodof claim 29 wherein filling material further comprises a polymericresin, filler, pigment, dye, antibiotic, cariostatic, antibacterial,anti-inflammatory, biologically active or therapeutic material.
 58. Themethod of claim 29 further comprising softening the filling material andinjecting the filling material through a needle into the canal.
 59. Themethod of claim 29 wherein the sealant comprises an acrylate,methacrylate, epoxy resin or mixtures thereof.
 60. The method of claim30 wherein the etchant comprises an organic acid or an inorganic acid.61. The method of claim 58 wherein the organic acid comprises aminoacid, acrylic acid, maleic acid, citric acid, ethylene diamine tetraacetic acid (EDTA), tartaric acid, itaconic acid, 5-sulfosalicylic acid,propionic, lactic acid, or derivatives or mixtures thereof.
 62. Themethod of claim 60 wherein the inorganic acid comprises phosphoric acid,nitric acid, hydrochloric acid, sulfuric acid, or derivatives ormixtures thereof.
 63. The method of claim 33 wherein the bonding agentcomprises an acrylate or methacrylate resin.
 64. A method for restoringthe root canal of a tooth comprising: preparing the root canal; applyinga sealant into the root canal; inserting a filling material into thecanal, wherein the filling material comprises a thermoplastic polymerand optionally, a bioactive filler, wherein the thermoplastic polymerbonds to the sealant at a bond strength equal to or greater than about 3MPa, wherein the thermoplastic polymer is a biodegradable polymerselected from the group consisting of polylactides, polyglycolides,polycaprolactones, polyanhydrides, polyamides, polyurethanes,polyesteramides, polyorthoesters, polydioxanones, polyacetals,polyketals, polycarbonates, polyorthocarbonates, polyphosphazenes,polyhydroxybutyrates, polyhydroxyvalerates, polyalkylene oxalates,polyethylene oxides, polyacrylates/methacrylates, polyalkylenesuccinates, poly(malic acid) polymers, polymaleic anhydrides,poly(methylvinyl) ethers, poly(amino acids), chitin, chitosan, andcopolymers, terpolymers, and combinations thereof; wherein the bioactivefiller is selected from the group consisting of bioglass, calciumphosphate, Portland cement, hydroxyapatite, tricalcium phosphate, a di-or polyphosphonic acid, an anti-estrogen, a sodium fluoride preparation,a substance having a phosphate to calcium ratio similar to natural bone,and mixtures thereof; and wherein the step of preparing the root canalcomprises applying an etchant to the walls of the root canal.
 65. Afilling material for cavities and root canals comprising: athermoplastic polymer having a bond strength when bonded to a root canalsealant equal to or greater than about 3 MPa; and optionally, abioactive filler; wherein the thermoplastic polymer is a biodegradablepolymer selected from the group consisting of polylactides,polyglycolides, polycaprolactones, polyanhydrides, polyamides,polyurethanes, polyesteramides, polyorthoesters, polydioxanones,polyacetals, polyketals, polycarbonates, polyorthocarbonates,polyphosphazenes, polyhydroxybutyrates, polyhydroxyvalerates,polyalkylene oxalates, polyethylene oxides, polyacrylates/methacrylates,polyalkylene succinates, poly(malic acid) polymers, polymaleicanhydrides, poly(methylvinyl) ethers, poly(amino acids), chitin,chitosan, and copolymers, terpolymers, and combinations thereof; andwherein the bioactive filler is selected from the group consisting ofbioglass, calcium phosphate, Portland cement, hydroxyapatite, tricalciumphosphate, a di- or polyphosphonic acid, an anti-estrogen, a sodiumfluoride preparation, a substance having a phosphate to calcium ratiosimilar to natural bone, and mixtures thereof.
 66. A filling materialfor cavities and root canals comprising: a thermoplastic polymer;wherein the filling material has a bacterial leakage rate of 13% or lesswhen testing leakage over a thirty day period using a split chambermicrobial leakage model; wherein the split chamber microbial leakagemodel comprises an upper chamber, a lower chamber and an obturated canaldisposed between and connected to the upper and lower chamber; whereinthe upper chamber comprises bacteria; wherein the lower chambercomprises broth; and whereby leakage is detected by a change in theoriginal color of the broth in the lower chamber.
 67. The fillingmaterial of claim 66 wherein the presence of bacteria in the lowerchamber changes the color of the broth.
 68. The filling material ofclaim 66 wherein the bacteria comprises S. mutans or S. faecalis. 69.The filling material of claim 66 wherein the broth comprises BasalBroth.
 70. The filling material of claim 69 wherein the broth furthercomprises a pH indicator.
 71. The filling material of claim 70 whereinthe ph indicator comprises Phenol Red.
 72. The filling material of claim66 wherein the original color is red and is changed to yellow uponleakage.
 73. The filling material of claim 66 wherein the leakage rateis about 6.7% or less.
 74. The filling material of claim 66 wherein theleakage rate is based on a test sample of 15 teeth.
 75. A fillingmaterial for cavities and root canals comprising: a thermoplasticpolymer; wherein the filling material has a bacterial leakage rate of13% or less when testing leakage over a thirty day period using a splitchamber microbial leakage model; wherein the split chamber microbialleakage model comprises an upper chamber, a lower chamber and anobturated canal disposed between and connected to the upper and lowerchamber; wherein the upper chamber comprises bacteria; wherein the lowerchamber comprises broth; and whereby leakage is detected by a change inthe pH of the broth in the lower chamber.
 76. The filling material ofclaim 74 wherein the leakage rate is about 6.7% or less.
 77. The fillingmaterial of claim 74 wherein the leakage rate is based on a test sampleof 15 teeth.
 78. The filling material of claim 1 wherein the bondstrength between the filling material and the root canal sealant ismeasured by: producing disks of filling material; leaving one side ofthe disks exposed; applying a cement sealant to the exposed side of thedisks; allowing the sealant to set; debonding the samples with a pushshear mold; recording the maximum load at which the cement cylindersbreak from the sample surfaces; and calculating the bond strengths usingthe load divided by the contact surface area of the cement cylinder. 79.The filling material of claim 78 wherein a Bencor test device is used todebond the samples.
 80. The filling material of claim 78 wherein thedisks are mounted in a mounting material before the application of acement sealant to an exposed side.
 81. The filling of material of claim78 wherein gelatin capsules are applied to the cement sealant to holdthe cement sealant under a load of 500 grams.
 82. The filling materialof claim 78 wherein producing disks of filling material comprisessoftening the filling material and placing it in to steel molds toproduce sample disks having a diameter of 15 mm and a thickness of 1.2mm.
 83. The filling material of claim 78 wherein the Bencor test devicecomprises a crosshead for debonding the samples and the speed of thecrosshead is about 0.02 in/minute.